1. Field of the Invention
The present invention relates to a communication system using animation and a server as well as a terminal device used for the communication system. According to the present invention, a user accesses to a server from a client via a network so that the user can remotely perform a conversation while watching animation of an actual or fictional human or the like virtualized by using a computer. In addition, the user can converse while watching animation of a person to whom the user talks.
2. Description of the Prior Art
In recent years, a technique for communicating with an actual or fictional human, animal, doll or character that are virtualized by using a computer has been researched and developed.
For example, Japanese unexamined Patent Publication No. 11-212934 discloses a technique for having a creature that is raised in a virtual space perform a predetermined action by inputting a command via an input device such as a mouse or a keyboard. According to the technique, a user takes care of a virtual pet using a computer. Specifically, the user feeds the pet, lays the pet down, praises the pet, reproves the pet or plays with the pet in a similar way to taking care of a real pet by using a computer. The pet is raised by the user as described above and the user can experience how to raise pet with confirming growth of the virtual pet via images and voices output from a display or a speaker. It is also possible to remotely raise the pet via a network.
As a method for matching an output timing of voices of life with an output timing of images thereof, there is proposed a method disclosed in European Patent No. 0860811 in which the voices are synchronized with the images for output and a method disclosed in Japanese Unexamined Patent Publication No. 10-293860 in which the images are synchronized with the voices for output. Above method enables production of animation and output of the voices at the same time with the animation; therefore, the user can realistically recognize the output images and voices. As a method for producing animation based on actual film images, there is proposed an animation synthesis technique by way of recognition of actual film images (P.98-106, December 1998, NTT Technical Journal). According to the technique, a portrait is automatically made by a picture and expressions of different opening states of eyes and a mouth and expressions of various emotions are automatically made based on the portrait. Then, the portrait is synchronized with a voice so that portrait animation can be synthesized.
In the above-described technique disclosed in Japanese Unexamined Patent Publication No. 11-212934, the user can remotely communicate with the virtual pet via the network. In the conventional technique, however, the virtual pet is controlled by commands from the user that are input via the input device so as to be displayed on the display; therefore, the user can communicate with the virtual pet only in limited patterns. For example, the technique does not allow conversation between the user and the virtual pet; therefore, realistic communication cannot be achieved by the technique.
The technique for producing the animation disclosed in European Patent No. 0860811 enables production of the animation including a motion of a person who is talking, for example. However, the user and the person cannot talk to each other, since the voices and the images are output uni-directionally from the person to the user.
A communication system such as a television telephone or a television conference system is actually utilized, in which a conversation can be performed with watching a partner's face by transmitting and receiving voices and images among a plurality of terminal devices.
However, since the images have a large amount of data, a communication line having large capacity for communication is required in order to transmit and receive the images. In the case of transmission and reception of images via a general telephone line, it is impossible to send and receive more than a few frames as an image per second and, therefore, it is impossible to display a satisfactorily animated image. In turn, the usage of a high-speed private line enables display of animated images wherein a motion appears substantially natural, however, it has not been widely prevalent yet due to high communication cost.
In order to reduce communications traffic, there has been proposed a method in which images of a part of and whole parts of a face are previously produced at low resolution for registration in a database, and then the whole facial image is displayed on a screen of a receiver's terminal device at the start of a conversation and only a part of the facial image corresponding to a part in which expressions have changed is downloaded from the database to the terminal device so as to be displayed in Japanese Unexamined Patent Publication No. 10-200882.
Reduction in the communications traffic can be realized by using the above-described conventional method. However, it is difficult to express a natural motion such as person's expressions since the resolution of the images is low and a plurality of two-dimensional images is continuously combined so as to be displayed.
Additionally, since respective users performing a conversation by means of the communication system must understand a common language, it is impossible for users using different languages to utilize the communication system described above.